[WARNING] Player ability minecraft:mayfly was updated externally (expected disabled, was enabled).

java.lang.RuntimeException: stacktrace

at io.github.ladysnake.pal.impl.VanillaAbilityTracker.checkConflict(VanillaAbilityTracker.java:72) ~[55ad8d83-15a1-4133-a65b-63ec32f3ac62.jar:?]

at net.minecraft.class_3222.handler$zin000$checkAbilityConsistency(class_3222.java:3687) ~[intermediary-server.jar:?]

at net.minecraft.class_3222.method_7355(class_3222.java:1252) ~[intermediary-server.jar:?]

at com.fibermc.essentialcommands.PlayerData.updateFlight(PlayerData.java:245) ~[essential_commands-0.16.1-mc1.16.5%20(1).jar:?]

at net.minecraft.class_3222.handler$bdm000$onChangeGameMode(class_3222.java:6654) ~[intermediary-server.jar:?]

at net.minecraft.class_3222.method_7336(class_3222.java:1274) ~[intermediary-server.jar:?]

at com.robertx22.age_of_exile.dimension.rules.OnTickSetGameMode.onTick(OnTickSetGameMode.java:22) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at com.robertx22.age_of_exile.event_hooks.ontick.OnServerTick.lambda$static$1(OnServerTick.java:53) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at com.robertx22.age_of_exile.event_hooks.ontick.OnServerTick$PlayerTickAction.tick(OnServerTick.java:259) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at com.robertx22.age_of_exile.event_hooks.ontick.OnServerTick$PlayerTickData.lambda$tick$0(OnServerTick.java:236) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at java.util.ArrayList.forEach(Unknown Source) ~[?:?]

at com.robertx22.age_of_exile.event_hooks.ontick.OnServerTick$PlayerTickData.tick(OnServerTick.java:235) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at com.robertx22.age_of_exile.event_hooks.ontick.OnServerTick.onEndTick(OnServerTick.java:217) ~[Age-Of-Exile-1.16.5-2.1.5%20AOERPG.jar:?]

at net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents.lambda$static$2(ServerTickEvents.java:62) ~[9d161df3-4f54-484a-b69d-3efdeae1343c.jar:?]

at net.minecraft.server.MinecraftServer.handler$bpg000$onEndTick(MinecraftServer.java:6763) ~[intermediary-server.jar:?]

at net.minecraft.server.MinecraftServer.method_3748(MinecraftServer.java:853) ~[intermediary-server.jar:?]

at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:670) ~[intermediary-server.jar:?]

at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:257) ~[intermediary-server.jar:?]

at java.lang.Thread.run(Unknown Source) [?:?]

Ah, this is an issue fixed in 0.16.2-1.17.1, but I see you're on mc1.16.5. I'll see about porting the fixes back to 1.16.5, and will link here when they are published.

Just released version 0.17.0-mc1.16.5, which includes a fix that should resolve this issue.